Bisphenol analogs affected hepatic development and disrupted lipid homeostasis in zebrafish larvae

Evidence suggests that human exposure to endocrine-disrupting chemicals (EDCs), such as bisphenol A (BPA), is associated with abnormal liver development. However, the relevant mechanisms, especially the impact on lipid homeostasis during early-life development remain unclear. In this study, we exposed zebrafish embryos to BPA and its substitutes bisphenol AF (BPAF) and bisphenol G (BPG) for 6 days, with a series concentration of 0.5, 50, and 500 (for BPA and BPAF) or 250 (for BPG) μg/L. We found that an analog called BPG exhibited the strongest impact on the liver development of zebrafish larvae, causing a significant reduction in the fluorescence area of Tg (fabp10a:dsRed;ela3l:EGFP) transgenic zebrafish at low concentration (0.5 μg/L). At the same time, all three bisphenols caused structural damage to the liver and hindered yolk absorption. Zebrafish larvae whole body oil-red staining and lipidomic analysis showed the occurrence of lipid accumulation post 50 μg/L or higher bisphenol exposure, including the increment of phosphatidylcholines, lysophosphatidylethanolamines, diglycerides and sphingomyelins. The 10x single-cell RNA-Seq analysis revealed that exposure to bisphenol analogs significantly activated lipid accumulation, hepatic steatosis, lipid metabolism, and liver injury pathways in hepatocyte, and the downregulation of apoeb was associated with lipid homeostasis disruption. These findings facilitate a deep understanding of the mechanism by which bisphenols interfere with liver development and lipid metabolism.